Lens driving device and camera module comprising same

Abstract

A lens driving device according to an embodiment comprises: a movable unit on which at least one lens is mounted; a first coil and a driving magnet which face and interact with each other such that the movable unit is moved in the optical axis direction of the lens; a position sensor for sensing the position of the movable unit in the optical axis direction or a driver comprising the position sensor; and a positively magnetized magnet arranged to face the position sensor or the driver, wherein the positively magnetized magnet comprises a first side surface, which faces the position sensor and has a first polarity, and a second side surface, which faces the position sensor, which is arranged to be spaced from the first side surface in a direction parallel with the optical axis direction or arranged to abut the first side surface, and which has a second polarity that is the opposite of the first polarity of the first side surface, and the length of the first side surface in the optical axis direction may be equal to or larger than the length of the second side surface in the optical axis direction.

1 . A lens driving device comprising:
 a cover member;   a bobbin disposed in the cover member;   a coil disposed on the bobbin;   a driving magnet disposed between the bobbin and the cover member;   a sensing magnet disposed on the bobbin;   a sensor configured to sense a position of the sensing magnet;   a circuit board comprising a plurality of terminals formed on a lower end portion of the circuit board; and   two lower elastic members coupled with a lower portion of the bobbin and spaced apart from each other,   wherein the two lower elastic members electrically connect the coil and the circuit board.   
     
     
         2 . The lens driving device of  claim 1 , wherein each of the two lower elastic members is soldered directly with the circuit board. 
     
     
         3 . The lens driving device of  claim 1 , wherein the sensing magnet is overlapped with the coil in an optical axis direction. 
     
     
         4 . The lens driving device of  claim 1 , comprising an upper elastic member coupled with an upper portion of the bobbin,
 wherein the upper elastic member is integrally formed.   
     
     
         5 . The lens driving device of  claim 1 , wherein the cover member comprises an upper plate and a lateral plate,
 wherein the lateral plate of the cover member comprises first and second lateral plates opposite to each other, and third and fourth lateral plates opposite to each other, and   wherein the driving magnet comprises a first magnet disposed on the first lateral plate, and a second magnet disposed on the second lateral plate.   
     
     
         6 . The lens driving device of  claim 5 , wherein the driving magnet is not disposed on the third and fourth lateral plates. 
     
     
         7 . The lens driving device of  claim 6 , wherein the sensing magnet is disposed on a first surface of the bobbin facing the third lateral plate of the cover member. 
     
     
         8 . The lens driving device of  claim 6 , wherein the sensor is disposed on the circuit board, and
 wherein the circuit board is disposed on the third lateral plate of the cover member.   
     
     
         9 . The lens driving device of  claim 1 , wherein the coil comprises a first area overlapped with the sensing magnet in an optical axis direction,
 wherein the first area of the coil is not overlapped with the driving magnet in a first direction perpendicular to the optical axis direction, and   wherein one lateral plate of the cover member comprises an opening formed at a position overlapped with the sensing magnet in the first direction.   
     
     
         10 . The lens driving device of  claim 1 , wherein the driving magnet is fixed with a lateral plate of the cover member by an adhesive. 
     
     
         11 . The lens driving device of  claim 5 , wherein the cover member comprises an inner yoke extending from an inner edge of the upper plate,
 wherein the coil is disposed on a periphery of the bobbin,   wherein the bobbin comprises a recess formed on the periphery of the bobbin and forming a space between the bobbin and the coil, and   wherein at least a part of the inner yoke is disposed in the space between the bobbin and the coil.   
     
     
         12 . The lens driving device of  claim 8 , wherein the circuit board is disposed outside the third lateral plate of the cover member. 
     
     
         13 . The lens driving device of  claim 1 , wherein the sensing magnet is not overlapped with the coil in a circumferential direction along a periphery of the bobbin about an optical axis. 
     
     
         14 . A camera module, comprising:
 a printed circuit board;   an image sensor disposed on the printed circuit board;   the lens driving device of  claim 1  disposed on the printed circuit board; and   a lens coupled to the bobbin of the lens driving device.   
     
     
         15 . A mobile phone comprising the camera module of  claim 14 . 
     
     
         16 . A lens driving device comprising:
 a cover member comprising an upper plate and a lateral plate;   a bobbin disposed in the cover member;   a coil disposed on the bobbin;   a driving magnet disposed between the bobbin and the cover member,   a sensing magnet disposed on the bobbin;   a circuit board disposed on the lateral plate of the cover member;   a sensor configured to sense a position of the sensing magnet and disposed on the circuit board; and   a lower elastic member coupled with a lower portion of the bobbin,   wherein the lower elastic member is soldered directly with the circuit board.   
     
     
         17 . The lens driving device of  claim 16 , wherein the lower elastic member is electrically connected with the coil. 
     
     
         18 . The lens driving device of  claim 16 , wherein the sensing magnet is overlapped with the coil in an optical axis direction. 
     
     
         19 . The lens driving device of  claim 16 , comprising an upper elastic member coupled with an upper portion of the bobbin,
 wherein the upper elastic member is integrally formed.   
     
     
         20 . A lens driving device comprising:
 a cover member;   a bobbin disposed in the cover member;   a coil disposed on the bobbin; and   a driving magnet disposed between the bobbin and the cover member.